Before planting it is a good idea to find your USDA Zone info to determine your garden schedule. The most important data that the zone info tells us is average last frost and the lowest expected temperature for your area.

In Granite City you can figure out when you can plant four-o-clock flower by looking at the USDA zone info.

Planting Calendar for Four-o-clock flower

Frost tolerance for four-o-clock flower:	Not tolerant of frost.
When to plant:	After the last frost.

Since four-o-clock flower are not cold tolerant it is important to wait until after all chance of frost has passed before you can plant them.

The earliest that you can plant four-o-clock flower in Granite City is April. However, you really should wait until May if you don't want to take any chances.

The last month that you can plant four-o-clock flower and expect a good harvest is probably August. If you wait any later than that and your four-o-clock flower may not have a chance to fully mature. Starting your four-o-clock flower indoors is a great way to get them started a few weeks earlier.

Last Frost Date

On average the last frost has passed is on April 15 in Granite City. In the coldest months of winter you should expect an average low temperature of -5°F.

It's important to remember that the actual date of last frost is not always accurate because it is based on the USDA zone info for Granite City and it will vary from year to year. Since half of the time in Granite City you get a frost after April 15 be ready to protect your four-o-clock flower in the event of a late frost.

USDA Zone Info for Granite City

Here is the info for USDA Zone 6b.

Average Date of Last Frost (spring)	April 15
Average Date of First Frost (fall)	October 15
Lowest Expected Low	-5°F
Highest Expected Low	0°F

This means that on a really cold year, the coldest it will get is -5°F. On most years you should be prepared to experience lows near 0°F.

Plants to Grow in Granite City

You may be interested in your other planting guides for Granite City.